In recent years, use of mobile communications devices for voice telephone services, email or text messaging services and even multi-media services has become commonplace, among mobile professionals and throughout the more general consumer population. Mobile communication services provided through public cellular or PCS (personal communication service) type networks, particularly for voice telephone service, have become virtually ubiquitous across much of the world. The mobile communication services offered by a wireless carrier or operator of a mobile communication network to users or subscribers may include a caller identification (or caller ID) service. Such a caller ID service or feature generally involves the display of information identifying the specific caller that originated an incoming call received at the user's mobile device. Such caller-specific information typically includes the caller's name and/or the phone number of the caller. If the mobile device recognizes the caller ID as corresponding to, for example, one of the user's contacts in a contact list stored locally at the device, the mobile device may display a picture of the contact from the local data storage with the caller ID information.
Furthermore, many mobile service providers have been upgrading wireless networks to support packet-switched data communications services, which extend the common data communication capabilities of the wired domain to the wireless mobile domain. However, the transition of an existing communication infrastructure to support newer technologies may require a substantial investment of time and resources. As such, mobile communication networks must still rely on existing technology and any limitations associated with such technology to provide voice and data communication services to their subscribers. In a particular example, mobile communication networks based on Code Division Multiple Access (CDMA) cellular telecommunication standards generally do not support simultaneous voice and data communications for mobile devices on the networks. Thus, a challenge faced by operators of mobile communication networks based on CDMA technology is the delivery of a voice call to a user's cellular telephone with data in real-time. Although specialized mobile devices exist that are capable of operating simultaneously in two different modes for voice and data, respectively, the high rate of power consumption and cost of such devices may make them prohibitive or impractical for general mobile device users. Another option is to deliver the data portion of a message using Short Message Service (SMS) technology, which is supported by most cellular devices. However, the use of SMS may limit the amount or kind of data that can be delivered with an incoming voice call. Furthermore, using SMS for this purpose may reduce overall system performance and lead to poor user experience.